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Decadal Wind Chill Temperature Trends for Canada and the United States

Daily maximum and minimum winter wind chill temperatures (WCTs) were determined from 156 hourly surface stations spread throughout the United States (US) and Canada. Decadal trends of maximum and minimum WCTs for the winter months (DJF) during the 1980s, 1990s, and 2000s were found using linear regression analyses. During the 1980s, both maximum and minimum WCTs cooled across the western US and eastern Canada and warmed across Alaska, western Canada, and the eastern US. During the 1990s, minimum WCTs warmed across most of the US and Canada with small regions of cooling in western Canada and the south central US. Maximum WCTs during the 1990s warmed throughout eastern Canada and the western US with a narrow region of cooling extending from southeastern Alaska equatorward to the southeastern US. During the winters of 1999/2000 – 2008/2009, both maximum and minimum WCTs cooled across nearly all of the US and Canada, with the exception of the southeastern US where WCT trends were near zero. The decadal trends in maximum and minimum WCTs during each decade were within the range of ± 1°C decade-1 and were most closely linked to decadal trends in surface temperatures. In general, decadal trends of minimum WCTs were found to be larger in magnitude than maximum WCT trends.